It's well-known that Mercedes-Benz's Aufrecht, Melcher and Großaspach division, also known as AMG, is the one that makes all the cars with the racy bits in them. It's also well-known that each engine is painstakingly handcrafted by one person. It's fascinating, though, to watch the process from start to finish.
One of the joys of this video is that there's no narration. There's no doofus with a nasally voice calling out the play-by-play. It's just the pure joy of watching a master craftsman at work. Like you're right there. And it doesn't get any better than that.
Now the only question is what car that engine's being thrown into. Just look at how fat those pistons are.
This Is How Mercedes-AMG Hand-Builds Every Single Engine